The area of a piston of a force pump is 8 X 10⁴m². What force must be applied to the piston to raise oil (d = 780 Kg/mº) to a height of 6.0 m? Assume
the upper end of the oil is open to the atmosphere.​

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s. part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.